1. Field of the Invention
Exemplary embodiments of the present invention relate to a backlight assembly improved to support a light guide panel from being thermally deformed by heat generated from a light source unit and minimize overlapping of lights from the light source unit at a corner of the light guide panel, and a liquid crystal display (LCD) including the same.
2. Description of the Related Art
Generally, a liquid crystal display (LCD) displays an image utilizing electric and optical properties of liquid crystal. The LCD has been widely used in industrial fields since being relatively thin and light compared to other display devices while consuming less power and operating with a low driving voltage.
Such an LCD comprises an LCD panel constituted by injecting a liquid crystal between two hermetically sealed transparent substrates, and a backlight assembly that supplies light to the LCD panel. Being applied with a voltage, the LCD panel changes the alignment direction of liquid crystal molecules, thereby varying its optical transmittance and accordingly optically displaying an image.
A light source of the backlight assembly may comprise a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), and a flat fluorescent lamp (FFL). However, the CCFL is inadequate for a refined look of the product and limited in achieving lightness and compactness of the product. Therefore, recently, a light emitting diode (LED) having improved brightness, lifespan, and color purity is more frequently used for the light source. Moreover, whereas use of the CCFL has been decreasing as Restriction of the use of Hazardous Substances (RoHS) is reinforced, the trend is to use the LED made of environment-friendly materials.
The backlight assembly using the LED light source may be classified largely into a direct type and an edge-lighting type according to the structural factors including the arrangement of LEDs and the shape of a light guide panel. The direct-type backlight assembly is difficult to have a slim form since LEDs are arranged on a front side of the backlight assembly. In addition, a number of the LEDs required in the direct-type backlight assembly increase the cost.
On the other hand, the edge-lighting LED backlight assembly has LEDs mounted on both sides thereof and draws light through a light guide panel. Therefore, in comparison with the direct type backlight assembly, the edge-lighting type backlight assembly may have a smaller thickness, thereby achieving slimness of the product.
The light guide panel of the edge-lighting type backlight assembly may thermally expand and contract in the area direction. Accordingly, it is important to prevent the light guide panel from being damaged by the thermal deformation.
In addition, in the edge-lighting type backlight assembly, lights from the plurality of LEDs arranged on the both sides may overlap around corners of the light guide panel, thereby deteriorating uniformity of brightness and increasing the temperature at the corners.